Electric lamp



May 16, 1939. A. G. MUELLER ELECTRIC LAMP Filed June 9, 1956 m; rwm w im 6 6% mm A W Wm h fi A w Patented M... is, 1939 ELECTRICIAN.

Adolf G. man... 8trattord, 0onn., aloignor a General Electric Company, a corporation of New York Application June,9, 1936, Serial No. 84,303

9 Claims.

The present invention relates to electric sockets for lamps and the like, and particularly to sockets having provisions for preventing short circuit between the terminals of the sockets when the sockets are empty. One use of. sockets of this type is for strings of Christmas tree lights where there is some likelihood of short circuiting the conventional sockets by pieces of tin foil dropping between the terminals of one of the sockets or between the terminals of sockets of adjacent strings when the sockets are empty.

The object of my invention is to provide an improved construction for sockets of this type, and, for a consideration of what I believe to be novel and my invention, attention is directed to the accompanying description and the claims appended thereto. 4

In the accompanying drawing Fig. 1 is a sectional elevationof a socket embodying my invention, showing a lamp in the socket; Fig. 2 is an enlarged sectional elevation of a portion of the lower end of the socket, the socket being empty; and Fig. 3 is a top plan view, partly broken away, of the portion of the socket shown in Fig. 2.

Referring to -the drawing, the socket has a tubular base or husk I of suitable molded insulating material in which is carried a unitary assembly comprising a screw shell 2 having an inwardly extending flange 3 at the lower end thereof. On the lower side of the flange 3 is a disk l 01 insulating material having a hollow rivet 5 at the center which serves as the center terminal of the socket, and a hollow rivet 6 which serves as the second terminal of the socket, and helps secure the disk 4 to the flange 3. Diametrically opposite the rivet G is a hollow rivet l which further secures the disk to the flange 3. The rivet. 6 extends through an opening 8 in the flange and is further insulated from. the flange by a washer 9 of insulating material. Between the washer 9 and the head of the rivet is one end of an arcuate' spring ill. The washer 9 insulates this end of the spring from the adjacent portion of the flange 3. The other end of the spring i0 is riveted by'rivet i0 to-the underside ter of the member H is flxed a,contact ii, the

lower end of which is directly above the center terminal 5, and the upper end of which is adapted to cooperate with the center contact 01' a v6 through the spring to the screw shell.

plug threaded into the shell and to serve as the center contact of the socket. .On the upper side of the member ii is a washer l3 which insulates the upper end of the rivet it. Before assembly of the screw shell into the base I, line conductors l4 and i 5 are connected to the terminais 5 and 6, and the screw shell is then inserted through the upper end of the base with the conductors i4 and I5 extending through the lower end of the base. The space around the conductors is then filled with an insulating cement it which holds the screw shell in the base.

When the socket is empty the member ii is spaced above the bottom of the screw shell, as shown in Fig. 2. In this position the spring i0 is out of contact with the flange 3 of the screw shell, and the contact I2 is out of contact with the center terminal 5. Both the screw shell and the contact I2 are therefore insulated from the line conductors. Since the member ii sub- 0 stantially closes the lower end of the shell, pieces of tin foil or other metallic substances which fall into the screw shell cannot short-circuit the socket. When a plug, such as the plug ll of a lamp i8, is threaded into the screw shell, the center contact IQ of the plug engages the contact I! and forces the member ll inward to a position in which the lower end of the contact I 2 engages the center terminal 5. In this position the spring in is moved into contact with the 30 flange 3, completing a circuitfrom the terminal The rivet l0 which secures the spring to the member II also makes contact with the rivet 1, forming an additional electrical connection to the screw shell. When the plug is threaded out of the screw shell, spring Ill returns the member i l to the position shown in Fig. 2, breaking the circuits to the screw shell and to the contact i2.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. In an electric socket, a husk, a unitary assembly flxed therein comprising a screw shell having an inwardly extending flange, a member of insulating material in said screw shell substantially closing the shell, said member being movable inward in said shell by a plug threaded in the shell, line terminals carried by the screw shell, and a spring within the shell and carried thereby above said flange and connected in the circuit from one of the line terminals to the screw shell, said spring being normally spaced from said flange to interrupt said circuit and biasing said member outward, and said member moving said spring into contact withsaid flange as said member is moved inward, thereby completing the circuit from the line terminal to the screw shell.

2. in an electric socket, a husk, a unitary assembly flxed therein comprising a screw shell having'an inwardly extending flange, a disk of insulating material secured to the lower side of said flange, a center terminal and a second terminal carried by said disk, a member oi insulating material above said flange substantially closing said shell, said member being mowable inward in said shell by a plug threaded in the shell, and a spring within the shell and carried thereby above said flange connected to said second terminal and having its normal position spaced from said flange, said member forcing said spring into contact with said flange to complete the circuit to the shell as said member is moved inward.

3. In an electric socket a husk, a unitary assembly fixed therein comprising a screw shell having an inwardly extending flange, a member of insulating material in said screw shell substantially closing said shell and having a contact adapted to complete a circuit to said flange, line terminals carried by the screw shell, and a spring within the shell and carried thereby above said flange and connected between said contact and a line terminal, said spring biasing said member to a position breaking the circuit between said contact and said screw shell, said member being moved to a position completing the circuit to the screw shell by a plug threaded into the shell.

4. In an electric socket, a center terminal, a screw shell having an inwardly extending flange around said center terminal, a member of insulating material in said screw shell having a contact adapted to complete a circuit between said center terminal and the center contact of a plug threaded in the screw shell and having a contact adapted to complete a circuit to the flange of the screw shell, and an arcuate spring within the shell above said flange and connected between said last mentioned contact and a line terminal, said spring biasing said member to a position breaking the circuit to the screw shell and the center terminal and thereby preventing short circuit of the socket, and said member being moved to a position completing the circuits to the screw shell and the center terminal by a plug threaded into the shell.

5. In an electric socket, a husk, a unitary assembly fixed therein comprising a screw shell, a center contact carried by the screw shell, said screw shell and center contact comprising the socket terminals, a member of insulating material substantially closing the shell, said member being carried by the shell and movable inward in the shell by a plug threaded therein, a spring carried by and within the shell between the lower end of the shell and said member and arranged to bias said member outward, and means operated by inward and outward movement of said member for respectively closing and opening a circuit to one of the socket terminals.

6. In an electric socket, a husk, a unitary assembly fixed therein comprising a screw shell and a center contact carried. by the screw shell, said screw shell and center contact comprising the socket terminals, a member of insulating material substantially closing said shell, said member being moved inward in the shell by a plug threaded therein, a line terminal carried by the shell, a spring carried within the shell and arranged between the lower end of the shell and said member for biasing said member outward, said spring being adapted to be connected in the circuit between the line terminal and the shell, and a contact in said circuit arranged to contact said spring when said member is in its inner position and to be separated from said spring when said member is in its outer position.

7. In an electric socket, a husk, a unitary assembly flxed therein comprising a screw shell, a center terminal carried by the screw shell, said screw shell and center contact comprising the socket terminals, a member of insulating material fixed to the screw shell and closing the lower end thereof, contacts adapted to be connected to line conductors carried by said member, a disk of insulating material within said shell above said member, said disk substantially closing the shell and being movable inward in the shell by a plug threaded therein, spring means carried by the shell between said disk and said member for moving said disk outward in said shell, and normally open contacts in the circuit from one of the line conductors to one of the socket terminals, said contacts being closed by the inward movement of said disk.

8. In an electric socket, a husk, a unitary assembly fixed therein comprising a screw shell, a center terminal carried by the screw shell, said screw shell and center contact comprising the socket terminals, a member of insulating material fixed to the screw shell and closing the lower end thereof, contacts adapted to be connected to line conductors carried by said member, a disk of insulating material within said shell above said member, said disk substantially closing the shell and being movable inward in the shell by a plug threaded therein, a leaf spring carried by the shell between said disk and said member for moving said disk outward in said shell, said spring being connected in the circuit between one of the line contacts and one of the socket terminals, and normally open contacts in said circuit, said contacts being closed by inward movement of said disk.

9. In an electric socket, a husk, a unitary assembly fixed therein comprising a screw shell, a center terminal carried by the screw shell, said screw shell and center contact comprising the socket terminals, a member of insulating material'fixed to the screw shell and closing the lower end thereof, contacts adapted to be connected to line conductors carried. by said member, a disk of insulating material within said shell above said member, said disk substantially closing the shell and being movable inward in the shell by a plug threaded therein, a leaf spring carried by the shell between said disk and said member for biasing said disk outward in said shell, said spring being connected in the circuit between one of the line contacts and one of the socket terminals, and a contact adapted to cooperate with said spring to complete said circuit, said contact being separated from said spring when the disk isin its outer position.

ADOLF G. MUELLER.

v t CERTIFICATE OF CORRECTION. Patent No. 2,158,88lp May 16, 1939. ADOLF e. MUELLER.

It is hereby oei'tified that error appearein the printed specification of the above numbered patent requiring correction at follows: Page 2, first column, line 69, claim 6, after the-word "shell" ir mert a comma; line 70, same m, strike out and; and that the eaid Letters Patent -ahou1d be read with this oorrection therein that the same may conform to the record of the case 111 the Patent Office.

Signed. and sealed this Hth'day of July; A. D. 1959.

Henry Van Arsdale (Seal) Acting Commissioner of Patents. 

